Carburetor



June 6, 1933. 3 w w s co 1,912,468

CARBURETOR Filed Feb. 7, 1931 a Sheets-Sheet 1 INVENTOR 011 w. Maw

June 6, 1933. 3 w w s co 1,912,468

CARBURETOR Filed Feb. 7, 1931 5 Sheets-Sheet 2 6a IZILENTOR I g I g June 6, 1933. B. w. WESTCOTT 1,912,463

CARBURETOR Filed Feb. '7, 1931 f5 Sheets-Sheet 3 Patented June 6, 1933 UNITED STATES PATENT OFFICE BRAYTOII W. WESTCO-TT, OF DETROIT, MICHIGAN, ASSIGNOR TO ZENITH-DEIROIT (30B.-

IPORATION, OF DETROIT, HICHIG AN, A CORPORATION OF MICHIGAN CARBUBETOB Application filed February 7,1931. Serial No. 51!,163.

The present invention relates broadly to the carburetion art, and more particularly to an improved carburetor especially useful for internal combustion engines, and adapted to insure normal or ordinary operation thereof with maximum fuel economy, while perm1tting the obtaining of maximum power when the engine is called upon to perform an extra heavy duty.

with ordinary throttle controlled internal combustion engines, the proper mixture ratio of fuel and gas for urposes of maximum economy is not constant with varying load conditions. As the load, or the amount of work being done, varies, the quantity of the mixture must be varied as well as the quality or richness thereof. If a carburetor 1s 1mtiallv adjusted to give maximum fuel economy over its normal range of operation, there is imposed a limitation which will preclude the development of maximum power by the engine. On the contrary. if the carburetor is initially set rich enough to insure the develooment of the maximum power, there is an appreciable loss of efiiciency with respect to fuel consumption throughout the ma]or eriod of engine operation.

The conditions referred to have been recognized in the art, and several attempts have been made to rovide a carburetor bv means of which they may be nartiallv or entirely overcome It has been proposed. forexample. to provide carburetors havin normal and auxiliary fuel passages in which the auxiliary fuel messages were controlled by pressure conditions on the engine side of the carbue retor throttle. With such structures, when the throttle is wide open, and the engine prosumablv performing its maximum dutv. the pressure at the oint referred to drops. Provision is made for utilizin such a'dr n pressure for increasing the richness of the mixture.

In many cases it is desirable to utilizein addition to the ordinary hand operated throttle, an automatic governor throttle which is controlled independently thereof. With such aconstruction, it not infrequently happens that the driver of a car having a carburetor so equip ed, may have a wide open throttle at the engine as determined by t e governor do not require such an enrichment.

It lS one of the obiects of the resent inventlon to provide an improved carburetor construction characterized by provision for maximum fuel economy during normal periods of operation, and by provision for enrichment of the mixture during such times as the condition of operation of the motor fed by the carburetor requires such enrichment.

It is another of the objects of the present.

invention to provide an improved construction of the character referred to effective for use either with a carburetor having an automatic throttle control, or with a carburetor in which such throttle control is not provided.

In the accompanying drawings I have shown for purposes of illustration only, certainpreferred embodiments of the present invention. In the drawings:

Figure 1 is a side elevational View of a portion of a carburetor in accordance with the present invention in operative relation to an engine manifold, where provision for an automatic governor controlled throttle exists;

Figure 2 is a transverse sectional view on the line IIII of Figure 1, looking in the direction of the arrows;

Figure 3 is a view partly in'vertical section, and partly in elevation, of a carburetor constructed in accordance with the present invention;

Figure 4 is a partial sectional view similar to Figure 3 illustrating other features of the construction Figure 5 is a detail sectional view of the economizer valve;

Figure 6 is a detail elevational view of a guiding spider for the economizer valve;

Figure 7 isa detail sectional view of the check valve;

Figure 8 is a perspective view of the check valve removed from its housing; and

Figure 9 is a perspective view of the check valve retaining ring.

Having reference more particularly to Figure 1 of the drawings, there is illustrated a carburetor comprising a bottom section 2 and an upper section 3. The upper section terminates in a flange 4 by means of which the carburetor may be secured in operative relation to an engine manifold. In Figure 1 of the drawings this flange is shown as bolted to the lower flange 5 of a governor throttle section 6 likewise terminating in an upper flange 7. The flange 7 is in turn bolted to an attaching flange 8 on an inlet manifold 9. It will be understood by those skilled in the art that the inlet manifold delivers a gas and air mixture to the cylinders of the motor to which the manifold is connected.

Having reference more particularly to the detail figures of the drawings, it will be apparent that the bottom section 2 includes a fuel reservoir 10 within which is provided a float 11 having a pivotal mounting 12. The float is adapted, by reason of its movements determined by the level of the fuel in the chamber, to control the position of an inlet valve 14 which determines the admission of fuel through a suitable inlet connection 15.

The bottom casting 2 is also of such construction as to provide an air inlet chamber 16 the admission of air to which may be con trolled by the usual choke or strangle valve 17. The admitted air is adapted to pass upwardly through a venturi 18 into a mixing chamber 19 in the upper casting 3, the outlet from which is controlled by a suitable throttle 20 as is customary in the art. The throttle shaft 21 is illustrated in Figure 1 as being extended through the side wall of the upper section and provided with an operating handle 22. The closed position of the throttle may be controlled, as is customary in the art, by providing a fixed stop 23 with which is adapted to cooperate an adjustable stop screw 24 carried by t e o crating lever 22.

For delivering uel into the venturi, there is illustrated an outer nozzle 25 hereinafter referred to as a discharge tube, and an inner nozzle 26, hereinafter referred to as a power and accelerating nozzle. Laterally disposed with respect to the assembly just described a supplemental nozzle 27 likewise extend- 1ng into the venturi for delivering fuel thereto 111 accordance with the Zenith principle. The supplemental nozzle communicates through a passage 28 with a well 29 open at its upper end through a passage 30 to the air space above the fuel in the float chamber, it being understood that the float chamber itself'is open to the atmosphere as is customary in the art through a suitable vent, not shown. The well in turn receives its fuel from the float chamber through a compensator 31 having a calibrated fuel feeding orifice therethrough and effective, with the carburetor supplying fuel to the motor to which it is connected, for maintainin a fuel level in the well the same as the fuel evel in the float chamber.

Dipping into the fuel within the well is a quill 32 discharging at its upper end into a passage 33 terminating in an outlet port 34 adjacent the throttle, and effective for delivering an idling fuel supply to the motor. With the throttle in normal running position, the delivery of fuel through the idle quill ceases, and the fuel from the well passes into the venturi through the supplemental nozzle 27. As such times as the fuel level within the well drops to such a point as to partially uncover the passage 28, the supplemental nozzle is supplied with an emulsion of fuel and air, as understood in the art.

The discharge tube 25 is connected through ports 35 with a passage 36 communicatin with the float chamber through a calibrate openng in a plug 37 which controls the fuel delivery to the discharge tube. Thus, during normal running conditions, the fuel is delivered to the venturi through a discharge tube responsive to suction and deliverin a quantity of fuel varying with suction, WlllCh quantity is augmented by the fuel supply through the supplemental nozzle, this quantity being virtually independent of suction at such times as the passage 28 is partiall uncovered and responsive only to the hea of fuel effective on the compensator 31, whereby the delivery through the supplemental nozzle is a substantially constant quantity per unit of time.

Formed in the bottom section 2 at one side of the well 29 is a cylinder 38 within which works a plun er 39. Connected to the plunger throng the medium of a ball and socket connection 40 is a rod 41 having a similar connection 42 at its upper end to an economizer and accelerating piston 43. The upper surface of the piston may be exposed, by means of passages 44 and port 45, tothe chamber 19 above the throttle 20. In such cases, with the throttle partly opened, for example, and the motor to which the carburetor is connected functioning, there will be a relatively high vacuum above the throttle. This vacuum will be transmitted by way of the port 45 and passages 44 to the plston 43 and will be efi'ectlve for holding it in the position illustrated in Figure 4 against the action of a spring 46.

Should, however, the throttle be suddenly opened, the absolute pressure above the throttle will increase to such an extent that it will not be effective for holding the piston 43 in its upper position. At such time, the spring 46 will depress the plunger 39 and bring it into engagement with the stem 47 of an economize! valve 48. This economizer valve is normally carried b a valve casing 49, illustrated in detail in igures 5 and 6, and guided by a spider 50. Between the spider and the valve is a spring 51 effective under normal conditions for maintaining the, valve '48 against its seat. When the valve stem 47 is engaged by the plunger 49 the pressure of the spring 51 will be overcome, and the valve 48 moved away from its seat. Such downward movement of the plunger will also be effective through a passage 52 for closin a check valve 53 against its seat 54 in a c eck valve casing 55. As will be apparent from the drawings, pressure against the under side of the valve 53, which is a gravity operated valve, will be effective for raising the same against the action ofogravity and thereby cutting off communication between the oat chamber 10 and the cylinder 38-, thus preventing any fuel which is within the cylinder '38 from being forced backwardly into the fioatchamher. The fuel will thus be caused-to pass the economizers valve 48 into a passage"56 communicating with the discharge tube 25. A .sudden descent of the plunger tl9 will'thus deliver a sudden charge to the yenturi at such times as afsudden deman'jdfor more fuel is made by the motor. If the'condition of increased fuel demand continues, the

plunger 39 will remain in its lower position,

and upon the release of accumulated fuel from the cylinder 38, the check valve 53 will again drop downwardly by gravity and establish a fuel flow directly from the float .chamber to the discharge tube by way of the check valve 53, passage 52, cylinder 38,

economizer valve 48 and passage 56.

It may be assumed thatthc condition just described exists at such times as the motor is running at highspeed or underheavy loads.

Should the speed be. decreased by partially closing the throttle, the absolute pressure in the chamber 19 above the same will decrease and the lunger 39 will again be raised, thus permltting the economizer valve to close the establishing normal fuel flow to the carburetor through the discharge tube and the supplemental nozzle.

The operation just described is representative of the operation when only a hand throttle is utilized. Where, however, itis desired tonse a governor controlled throttle, the relationship of the parts will be as shown in the drawings. In'such case, the port 45.will

be cut off from communication with the passages 44 by the insertion of a plug 57.

At the same time a pressure connection 58 will be established with the passages-44 to a suitable point 59 within the manifold 9 above the governor throttle section 6. Within th s j section is a throttle valve. 60 connected through a. suitable arm 61 to an operating rod 62-lea'ding to a suitable governor, not shown. In such case, it wlllbe apparentthat even ally operating only on part open throttle.

If-the position of the economizer and accelerating piston assembly were determined by conditions above the hand throttle 20by reason of use of the port 45, the plunger 39 would be permitted to lower and enrich the mixture. With the connection 58, however, the actual pressure conditions above 'the hand throttle 20 will not be utilized, the connection 58 transmitting to the economizer and accelcrating piston assembly only the pressure clonditions existing above the governor thrott e. r

Thus, under the conditions described, with partly open governor throttle, the vacuum in the manifold will be high-enough to'retain the economizer and accelerating piston assembly in elevated position and thus insure normal fucldelivery only to the motor. If,

however, the load on the engine is increased in such manner that the governor moves the throttle 60 to its wide open pos tion, the absolute pressure conditions existing with n the manifold will morenearly approach the pressure conditions below such throttle. The vacuum will not then be such as to maintain the economizer and accelerating piston assembly in its elevated position aga nst the combined action of gravity and the action of the spring 46, and the plunger 39 will lower, thus opening the economizer valve 48, closing the check valve 53, and delivering an enrichening charge to the engine. Thereafter, after exhausting the fuel in the cylnder 38 and relieving the pressure from the under side ,of

the check valve 53, the enrichening fuel flow operating efliciency. it affects an increase in power, as required for'the then existing conditions.

As soon as'the load requirements of the engine have decreased to such a' point that the governor returns the throttle 60 to its partly closed position. the higher vacuum conditions above th s throttle "will be transmitted to the econom zer and accelerating piston assembly in such manner as to close the enrichening'source of supply through the economizer valve and thus re-establish normal operating conditions.

The construction thus provides means for furnishing an economical mixture for normal requirements, or a richer mixture for abnormal or special requirements such as represented by high speeds or maximum loads. It is also effective for delivering a measured charge or fuel addition at times of rapid change in requirements as determined by a sudden throttle opening, the plunger 39 at such times operating as a pump, as will be readily apparent.

The present invention thus provides a carburetor which may be adjusted to satisfactorily meet all normal requirements of the engine serviced thereby with respect to normal power requirements and maximum eiiiciency, and automatically controlled in such manner that only during periods of actual requirement, as determined either by the hand throttle or the governor throttle, are the characteristics of the mixture so modified as to give increased power with corresponding decrease in power eificiency.

Further advantages of the present invention arise from the fact that the construction provided is such that it is adapted to use either under normal conditions not involving the presence of a governor throttle, or under special conditions where such a throttle is desired. The change may be easily effected by removing the connection 58 and substituting a suitable closure plug and removing the plug 57 for effecting control by the hand throttle, or by inserting the plug 57 and establishing the connection58 for effecting control by the governor throttle. This makes it unnecessary to provide special carburetor structures for special processes;

The opening 63, as indicated in Figure 4, prevents fuel being lifted upwardly into the piston chamber in case of a suction leak around the piston 43. It is therefore provided as a matter of practical expediency and constitutes a safety feature.

While I have herein shown and described certain preferred embodiments of my invention, it is to be understood that changes in the construction and operation of the parts may be made without departing either from the spirit of the invention or the scope of my broader claims.

I claim:

1. Ina carburetor, an air system including a hand operated throttle, connections for providing a governor controlled means inwardly thereof, a fuel system delivering into said air system, means for changing the richnefs of the mixture delivered by said fuel system, and connections for making said last mentioned means responsive either to pressure conditions in said air system inwardly of said hand operated throttle orinwardly of said governor controlled means where such governor controlled means is provided.

2. In a carburetor, an air system including a hand operated throttle, and a overnor controlled means inwardly thereo a fuel system delivering intosaid air system, means controlled by pressure conditions in said air system inwardly of said governor controlled means for changing the richness of the mixture delivered by said fuel system, and means for insuring a temporary enrichening change prior to the establishing of the changed mixture delivery.

3. In a carburetor, an air system including a hand operated throttle, a governor controlled means inwardly thereof, a fuel system including a nozzle for normally delivering fuel to said air system below said throttle, a second nozzle operative in response to the aspirating effect of said air system for delivering enrichening fuel to said air system below said throttle, and means responsive to engine requirements as determined by said governor controlled means for controlling the delivery of fuel to said last mentioned 7 nozzle.

4. In a carburetor, an air system including a venturi, a fuel system for delivering fuel thereto and including a. plurality of nozzles terminating within said venturi, means effective for normally delivering fuel through part only of said nozzles, vacuum operated pump means effective for delivering an accelerating charge through another of said nozzles, and valve means controlled by said pump means and effective after delivery of the accelerating charge to continue the dclivery of an enrichening charge through said last mentioned nozzle.

5. In a. carburetor, an air system including a venturi, a nozzle system for delivering normal fuel-supply to said venturi, a supplemental nozzle system for delivering an enrichening charge to said venturi, said supplemental nozzle system including an operative connection to a source of fuel supply and containing both a check valve and economizer valvenormally so positioned as to prevent the supply of fuel through the supplemental nozzle system, and means for first closing the check valve and then opening the economizer valve for delivering an accelerating charge through said supplemental nozzle system and thereafter establishing an enrichening flow through saidrsupplemental nozzle system from said source of supply.

6. In a carburetor, an air system, a nozzle system for normally delivering-fuel to the air system, a supplemental nozzle system having a flow passage including both a normally closed economizer valve and normally open check valve, and fluid pressure operated means for opening said economizer valve and temporarily closing said check valve. 7

7. In a carburetor, an air system and a float chamber, a nozzle system for delivering normal fuel supply to said air system fromj said float chamber, and including a connection with said float chamber, a supplemental nozzle system for delivering anenrichening charge to said air system and including a second separate connection to said float chamber, said second connection containing both a check valve and an economizer valve normally so positioned as to prevent the supply of fuel through the su plemental nozzle system, and means for rst closing the check valve and then opening the economizer valve for delivering an accelerating char through said supplemental nozzle system without disturbing the fuel flow through said first mentioncd nozzle system, and thereafter establishing an enriching flow through said suppleme'ntal nozzle system from said float chamber.

8. In a carburetor, an air system and a float chamber, a nozzle system for delivering normal fuel supply to said air system from said float chamber, and including a connection with said float chamber, a supplemental nozzle system for delivering an enrichening charge to said air system and including a second separate connection to said float chamber, said second connection containing both a check valve and an economizer valve normally so positioned as to prevent the supply of fuel through the supplemental nozzle s stem, and vacuum operated pump means or first closing the check valve. and then opening the economizer valve for delivering an accelerating charge through said supplemental nozzle system without disturbing the fuel flow through said first mentioned nozzle system, and thereafter establishing-an enrichening flow through said sup lemental nozzle system from said float cham er.

, In testimony whereof I have hereunto set my BRAYTON w. WEsTco'r'r.

CERTIFICATE or CORRECTION.

I Patent No. 1,912, 58.

BRAYTON-W. wrsrcorr.

It is hereby certitiedthat error appears in the printed specification of the line 24, for

above numbered patent requiring correction as follows: Page 3, "economizers" read "economizer"; and line 47, for "the" read "and"; page 4,

line 73,'elaim 2, for "change" read "charge"; ind mam said Letters Patent should be read with these corrections therein that the same may conform to the v record of the ease in the Patent Office. L

Signed and sealed this 8th day of August, A. D. 1933.

I M. J; Moore.

(Seal June. 6, 1933.

- Acting Commissioner of Patents.

tion with said float chamber, a supplemental nozzle system for delivering anenrichening charge to said air system and including a second separate connection to said float chamber, said second connection containing both a check valve and an economizer valve normally so positioned as to prevent the supply of fuel through the su plemental nozzle system, and means for rst closing the check valve and then opening the economizer valve for delivering an accelerating char through said supplemental nozzle system without disturbing the fuel flow through said first mentioncd nozzle system, and thereafter establishing an enriching flow through said suppleme'ntal nozzle system from said float chamber.

8. In a carburetor, an air system and a float chamber, a nozzle system for delivering normal fuel supply to said air system from said float chamber, and including a connection with said float chamber, a supplemental nozzle system for delivering an enrichening charge to said air system and including a second separate connection to said float chamber, said second connection containing both a check valve and an economizer valve normally so positioned as to prevent the supply of fuel through the supplemental nozzle s stem, and vacuum operated pump means or first closing the check valve. and then opening the economizer valve for delivering an accelerating charge through said supplemental nozzle system without disturbing the fuel flow through said first mentioned nozzle system, and thereafter establishing-an enrichening flow through said sup lemental nozzle system from said float cham er.

, In testimony whereof I have hereunto set my BRAYTON w. WEsTco'r'r.

CERTIFICATE or CORRECTION.

I Patent No. 1,912, 58.

BRAYTON-W. wrsrcorr.

It is hereby certitiedthat error appears in the printed specification of the line 24, for

above numbered patent requiring correction as follows: Page 3, "economizers" read "economizer"; and line 47, for "the" read "and"; page 4,

line 73,'elaim 2, for "change" read "charge"; ind mam said Letters Patent should be read with these corrections therein that the same may conform to the v record of the ease in the Patent Office. L

Signed and sealed this 8th day of August, A. D. 1933.

I M. J; Moore.

(Seal June. 6, 1933.

- Acting Commissioner of Patents. 

